Debate concerning entrepreneurship has focused on three questions; the contribution of entrepreneurs to development; the definition of the entrepreneurs role; and the degree to which personality and cognitive factors vs. socio-economic ones can best explain the supply of entrepreneurs in a developing economy. The focus of the study is the latter question but research is intended to illuminate the former questions as well. Several scholars have suggested that entrepreneurs constitute a distinct personality type while others have urged that they are members of specific types of socio-economic groups. The study focuses on one such group which meets Hagen's definition of criteria of groups which supply entrepreneurs; namely, those who members have undergone long-term status withdrawal. Mestizo stall- vendors of Patzcuaro, Mexico, have previously engaged in selling produce on the basis of daily ability to acquire stock and pay a small "stock tax." This arrangement made for great economic flexibility. Four years ago a market building was constructed to house all such vendors; stalls, which are rented for a monthly rate determined by stall-size rather than stock-size, are seen by the investigators as a mechanism for selecting out those vendors who are able to innovate new economic behavior and to rationlize market costs. The aim of the research is to isolate the cognitive, social and economic factors which account for successful entrepreneurial activity under the new socio-economic constraints. Interviews will be conducted with selected vendors from both the group which has continued as vendors and those which have not. Information to be gathered in each group concerns life-histories, social and economic resources and values. It is hoped that an empirical study of the way in which these factors condition the supply of entrepreneurs in a developing economy will amplify the current theoretical literature. It should also provide information for policy recommendations affecting formerly low-status poor, especially minority groups, in the United States who are reluctant to engage in innovative economic activity.